Interaction mechanism of oseltamivir phosphate with bovine serum albumin: multispectroscopic and molecular docking study.

Oseltamivir phosphate (OP) is an antiviral drug with potential risks to human health due to overuse, leading to serious consequences such as gastrointestinal disturbances, abnormal neuropsychiatric symptoms, and sudden death. Therefore, gaining an in-depth understanding of its interaction with proteins is crucial. We investigated the interaction between OP and bovine serum albumin (BSA) utilizing multispectral methods (i.e., fluorescence, ultraviolet absorption, circular dichroism) combined with molecular docking techniques. Fluorescence spectroscopy indicated that OP quenched BSA fluorescence by forming the OP-BSA complex. The Stern-Volmer constants (KSV) between OP and BSA were determined to be 3.06 × 103 L/mol, 2.36 × 103 L/mol, and 1.86 × 103 L/mol at 293 K, 298 K, and 303 K, respectively. OP occupies exclusively one binding site on BSA, and the fluorescent probe displacement measurements revealed that this is BSA site I. Thermodynamic data (∆H, ∆S, and ∆G) obtained by fitting the van't Hoff equation were - 77.49 kJ/mol, -176.54 J/(mol∙K), and - 24.88 kJ/mol, respectively, suggesting that hydrogen bonding and van der Waals forces mainly participate in OP-BSA complex stabilization. Moreover, the reaction occurs spontaneously at room temperature. Synchronous fluorescence spectra indicated that OP interacts with tryptophan residue of BSA. The results of ultraviolet (UV) and 3D fluorescence spectroscopy indicated that the OP-BSA complex formation altered the microenvironment around amino acid residues. Circular dichroism spectra revealed that the addition of OP decreased the α-helix content of BSA by 7.13%. Docking analysis confirmed that OP binds to BSA site I through hydrogen bonding with amino acids VAL342, SER453, and ASP450. Finally, ADMET studies were conducted to explore the pharmacokinetics of OP as an antiviral drug.

Prognostic value of hypothyroidism in patients undergoing intensity-modulated radiation therapy for nasopharyngeal carcinoma.

BACKGROUND: The purpose of this study was to investigate the effect of hypothyroidism and thyroxine replacement therapy on the prognosis of nasopharyngeal carcinoma (NPC) patients. METHODS: The clinical data of 284 NPC patients, who received intensity-modulated radiation therapy (IMRT) between January 2011 and December 2016, were retrospectively analyzed. RESULTS: Hypothyroidism occurred in 38% of patients. Patients with hypothyroidism had significantly better disease-free survival (DFS) (p = 0.002) and relapse-free survival (RFS) (p = 0.008). Multivariate analysis showed that hypothyroidism was a positive independent prognostic factor (DFS and RFS). Among the patients with hypothyroidism, thyroxine replacement therapy did not yield inferior survival (DFS, RFS, all p > 0.05). CONCLUSIONS: The NPC patients with complete response are at risk of hypothyroidism, which is attributable to escalating dose. These patients experienced clinical hypothyroidism could be adequately treated with thyroid hormone replacement. Further investigation of the underlying biological mechanism and potential therapeutic implications are required.

Binding interaction of sodium benzoate food additive with bovine serum albumin: multi-spectroscopy and molecular docking studies.

Sodium benzoate (SB) is widely used as a preservative in food industry, and bovine serum albumin (BSA) is a major carrier protein similar to human serum albumin (HSA), the study of the binding between the two has great significance on human health. In this paper, we systematically investigated the binding of SB and BSA under the simulated physiological conditions combining with various common analytical methods, e.g., fluorescence, UV-vis absorption, synchronous fluorescence and circular dichroism (CD) spectra, as well as molecular docking method. The fluorescence quenching measurements were respectively carried out at 298 K, 303 K and 308 K using the Stern-Volmer method. The results reveal that ground state SB-BSA complex was formed within the binding constants from 2.02 × 104 to 7.9 × 103 M-1. Meanwhile, the negative values of ΔH 0 (- 43.92 kJ mol-1) and ΔS 0 (- 111.6 J mol-1 K-1) demonstrated that both the hydrogen binding interaction and van der Waals forces contributed to stabilizing the SB-BSA complex. The site marker competitive experiments show that the SB and BSA bound at site I. Furthermore, the experimental results of UV-vis absorption, synchronous fluorescence and CD spectra indicate that the binding of SB and BSA may change the conformation of BSA. In addition, the molecular docking experiment suggests that hydrogen bond was formed in the interaction between SB and BSA.

A study on the value of narrow-band imaging (NBI) for the general investigation of a high-risk population of nasopharyngeal carcinoma (NPC).

BACKGROUND: This study aims to explore the feasibility of narrow-band imaging (NBI) applied for the diagnostic screening of a high-risk population of nasopharyngeal carcinoma (NPC) and increase the accuracy rate of nasopharyngeal biopsy and the diagnosis rate of early-stage patients. METHODS: The positive high-risk population of NPC to EB virus antibody was followed up. At the same time, serological screening and pharyngorhinoscopy were carried out. The specific methods were as follows: (1) all subjects received nasopharyngeal examinations through both the HD endoscopic white light mode (WL) and NBI mode, (2) nasopharyngeal biopsy was conducted on positive subjects with microscopic examination, and, finally, (3) a comparative analysis was conducted between the biopsy pathology results and microscopy results. In addition, the following comparative indicators were recorded under different modes: sensitivity, specificity, accuracy, positive likelihood ratio, and negative likelihood ratio. Then, the area under the ROC curve and the kappa coefficient were calculated. RESULTS: A total of 115 subjects were detected to be positive by microscopic examination under the WL mode. Among these subjects, 19 subjects were diagnosed with NPC. In addition, 24 subjects were detected to be positive by microscopic examination under the NBI mode. Among these subjects, 23 subjects were diagnosed with NPC. Under the WL mode, the specific values of the comparative indicators were as follows: sensitivity, 82.61%; specificity, 0%; and area under the ROC curve, 0.413. Furthermore, the WL mode in the diagnosis on the high-risk population of NPC exhibited poor consistency with the biopsy pathology results (kappa coefficient = - 0.069). Under the NBI mode, the specific values of the comparative indicators were as follows: sensitivity, 100%; specificity, 98.96%; and area under the ROC curve, 0.995. Furthermore, the NBI mode in the diagnosis on the high-risk population of NPC exhibited relatively satisfactory consistency with the biopsy pathology results (kappa coefficient = 0.973). Therefore, the NBI mode is significantly superior to the WL mode. CONCLUSION: NBI endoscopic examinations should be conducted on a routine basis for high-risk populations of NPC. This can decrease the frequency of biopsies and enhance diagnostic effects.

Influence of endoscopic sinus surgery on the quality of life of patients with early nasopharyngeal carcinoma and the analysis of prognosis-related factors.

The aim of this study is investigate the influence of endoscopic sinus surgery on the quality of life and prognosis of patients with early nasopharyngeal carcinoma. Patients initially diagnosed with early nasopharyngeal carcinoma and received surgical treatment were matched with nasopharyngeal carcinoma patients who received chemoradiotherapy at a ratio of 1:1, according to the following seven factors: gender, age, T staging, N staging, clinical staging, radiotherapy options, and chemotherapy options. Patients in the surgery group received endoscopic sinus surgery plus chemoradiotherapy, while subjects in the control group received chemoradiotherapy. The quality of life of patients before and after treatment was evaluated based on the FACT-H&N (Functional Assessment of Cancer Therapy-Head and Neck) and QLQ-H&N35 (Head and Neck Cancer Specific Module) questionnaires. In addition, overall survival and disease-free survival were compared between these two groups. The results showed overall survival was superior in the surgery group compared with the control group ( p = 0.007). However, the difference in disease-free survival between these two groups was not statistically significant ( p = 0.128). Furthermore, subgroup analysis revealed that for N0 patients, the effect of surgery combined with chemoradiotherapy on overall survival was superior to that of chemoradiotherapy ( p = 0.048); while for N1 patients, the difference in overall survival between these two groups was not statistically significant ( p = 0.065). For early nasopharyngeal carcinoma patients without lymph node metastasis, overall survival and disease-free survival in T1 patients were superior to those in T2 patients (χ2 = 4.403, p = 0.036; χ2 = 4.542, p = 0.033). At the end of treatment, the pain score was found to be significantly lower in the surgery group than in the chemoradiotherapy group ( p = 0.027). At 3 months and 1 year after treatment, dry mouth scores were significantly lower in the surgery group than in the chemoradiotherapy group ( p = 0.002, p = 0.026). These results demonstrated that the curative effect of surgery combined with chemoradiotherapy in the treatment of nasopharyngeal carcinoma was satisfactory and was particularly suitable for N0 patients.